Reliability of Hip Strength Assessment in Young Active People with Hip Dysplasia: An Examination in Student Circus Artists.

BACKGROUND: Developmental dysplasia of the hip (DDH) is common in performing artists and other young active individuals and involves abnormalities in bony morphology of the acetabulum and proximal femur that can negatively impact walking biomechanics, muscular strength, quality of life, and sleep. Rehabilitation for hip-related conditions should target known modifiable impairments such as hip muscle strength, though a reliable method of assessment in this population remains unclear. OBJECTIVE: To determine the inter- and intra-rater reliability of hip muscle strength assessments using handheld dynamometry (HHD) in young active circus artists with DDH. METHODS: Reliability of hip strength in all planes was assessed using HHD in 21 adult performing circus arts students (mean age 21.3 yrs [3.2]; 13 M, 5 F, 3 NB) with symptomatic radiologically and clinically diagnosed hip dysplasia. The reliability of average peak force and absolute peak force were expressed for each position tested. Reliability was assessed using intraclass correlation coefficients (ICC) with standard error of measurement (SEM) and minimal detectable change (MDC) values calculated to improve clinical interpretability. RESULTS: Good to excellent inter-rater reliability resulted for all hip muscle strength testing positions, ICC=0.88 (95%CI 0.70 to 0.95) to ICC=0.97 (0.92 to 0.99), except average peak hip flexion strength, ICC=0.71 (0.28 to 0.88). Absolute peak hip abduction, ICC=0.77 (0.16 to 0.94), and adduction strength, ICC=0.72 (-0.55 to 0.92), demonstrated the lowest intra-rater reliability. Transverse plane strength measures (rotation) produced the lowest SEM and MDC values followed by the frontal plane (abduction/adduction) and sagittal plane (flexion/extension). CONCLUSION: HHD is an appropriate and reliable method to assess hip muscle strength in circus artists with DDH.

Assessment of Isokinetic Trunk Muscle Strength and Fatigue Rate in Individuals after Bariatric Surgery.

Background and Objectives: Lean body mass loss after bariatric surgery (BS) is remarkable, despite an effective long-term mass reduction and significant declines in comorbidities. A person's functional capacity is adversely affected when their skeletal muscle strength declines by up to 30%. This study aimed to assess the isokinetic trunk muscle strength and fatigue rate in individuals after BS. Materials and Methods: This study included fifty-eight patients, both male and female, ranging in age from 19 to 45. Twenty-seven individuals had BS and twenty-seven healthy people served as the control group. The primary outcomes were the measurement of the concentric and eccentric isokinetic muscle strength of the trunk flexor and extensor muscles. An isokinetic dynamometer (Biodex Rehabilitation and Testing System 3) was used for the assessment of the isokinetic muscle strength. Noraxon EMG was used to determine a secondary outcome, which was the median frequency slop (MF/time) and root mean square slop (RMS/time) of the lumbar erector spinea muscle at 50% of the Maximum Voluntary Isometric Contraction (MVIC). Outcome measures were assessed for both groups. Results: Compared to the control group, the bariatric group showed a lower mean value of both concentric and eccentric isokinetic muscle strength for the flexor and extensor trunk muscles (p < 0.05). In terms of the EMG fatigue rate, the RMS slope increased significantly more than that of the control group, while the MF slope decreased (p > 0.05). Conclusions: The current study found that, in comparison to the healthy subjects, the BS group showed reduced levels of fatigue and isokinetic strength in the trunk muscles. Based on these results, it is recommended that individuals who underwent BS take part in tailored rehabilitation programs to avoid potential musculoskeletal issues in the future.

Intersession reliability of lower limb muscle strength assessments in adults with obesity eligible for bariatric surgery.

BACKGROUND: The aim of this study was to examine the test-retest reliability in lower limb muscle strength and rate of torque development (RTD) using isokinetic dynamometry in adults with obesity, with a body mass index (BMI) ≥ 35 kg/m2. METHOD: Thirty-two adults with a BMI of 43.8 ± 6.6 kg/m2 eligible for bariatric surgery were enroled in the study. Isokinetic and isometric knee extensor (KE) and flexor (KF) strength were assessed in an isokinetic dynamometer (Biodex 4) during three test sessions separated by 3-7 days. RESULTS: There were no statistical differences in peak KE and KF torque for any test modalities between sessions. Intraclass correlation (ICC) was 0.91-0.94 between sessions 1 and 2 and 0.94-0.97 between sessions 2 and 3. Standard error of measurement (SEM%) and coefficient of variation (CV) ranged across test sessions from 4.3% to 7.3%. KE RTD showed high test-retest reliability following familiarization, with ICC, CV and SEM% values ranging from 0.84 to 0.90, 13.3%-20.3% and 14.6%-24.9%, respectively. CONCLUSION: Maximal lower limb muscle strength measured by isokinetic dynamometry showed excellent test-retest reliability manifested by small measurement errors and low CV. Reliability was slightly improved by including a familiarization session. KE RTD but not KF RTD demonstrated high test-retest reliability following familiarization. The present data indicate that isokinetic dynamometry can be used to detect even small changes in lower limb muscle strength in adults with obesity.

Reliability, Concurrent Validity, and Minimal Detectable Change of the Hand-Held Dynamometry for the Assessment of Knee Muscle Strength in Patients With Revision Total Knee Arthroplasty.

OBJECTIVE: To determine the concurrent validity, reliability, and minimal detectable change (MDC) of the hand-held dynamometry (HHD) for knee strength measurement in patients with revision total knee arthroplasty (r-TKA). DESIGN: A reliability and validity analysis. SETTING: Orthopedic and physical therapy services of university hospital. PARTICIPANTS: The study included 42 patients with r-TKA (N=42). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Knee muscle strength assessments were performed by 2 physiotherapists in 3 different sessions by using HHD. Participants were instructed to exert a maximal force for lasting 5 seconds against HHD. The first examiner performed the strength testing, and after 30-minutes rest, the second examiner performed the same procedure for inter-examiner reliability. One hour after the initial testing, the first examiner reperformed the strength testing for intra-examiner reliability. The correlations of the knee extensors and knee flexors strength with 50-foot walking test and 30-second chair stand test were assessed for concurrent validity. RESULTS: The inter-examiner reliabilities of knee extensors and flexors strength measurements were 0.97 and 0.95, respectively. The SEM and the minimal detectable changes at 95% confidence level (MDC95) for knee extensors were 10.39 and 28.65 Newton-meters (Nm), and SEM and MDC95 for knee flexors were 8.70 and 23.99 Nm, respectively. The intra-examiner reliabilities of knee extensors and flexors strength measurements were 0.96. SEM and MDC95 for knee extensors were 12.00 and 33.09 Nm, and SEM and MDC95 for knee flexors were 7.78 and 21.45 Nm, respectively. The knee muscle strength showed strong significant correlations with physical performance tests (all, P<.05). CONCLUSIONS: The HHD is a reliable and valid method for assessment of static knee strength after r-TKA. The HHD can be used to quantify changes in knee strength and also assists the clinicians to determine the effect of rehabilitation programs on muscle strength following r-TKA surgery.

Study of Reliability and Validity of the Load Cell-Type Hand Dynamometer Compared to the Jamar Dynamometer and the Number of Reliable Grip Strength Measurements.

Background: Standardised measurement protocols for grip strength remained unclear due to variations in values depending on the device and measurement method. The load cell hand dynamometer has recently been developed. This study aims to investigate the reliability of the load cell dynamometer by comparing it to the Jamar dynamometer, which is considered the gold standard, and to identify a reliable and practical measurement method. Methods: This study included 80 healthy hospital workers (mean age of 40.1 years). All measurements were performed seated, with the elbow flexed 90° and the grip span at the second handle (approximately 50 mm) for the Jamar dynamometer, and with the elbow extended and the grip span fixed at 55 mm for the load cell dynamometer. Grip strength was measured three times on each hand using two dynamometers, and the same tests were repeated on different days. Test-retest reliability, the association between the two devices and the agreement between the two measurement methods were assessed using the intraclass correlation coefficient (ICC), Pearson correlation and the Bland-Altman analysis. Results: The ICC of the one measurement was lower than that of three measurements for both dynamometers, but was above 0.858 in all groups, indicating sufficient reliability with one-time measurement. Additionally, the ICC for different days revealed good reliability (Jamar: >0.830, load cell: >0.772). The load cell dynamometer showed significantly lower values in all measurements despite the excellent correlation (r > 0.70) and the agreement between the two dynamometers. Conclusions: This study revealed sufficient reliability of the load cell dynamometer with the standardised measurement method, but it should be noted the lower values compared to the Jamar dynamometer. Additionally, one-time measurement reliability is adequate for practical use by standardising the measurement methods for both dynamometers. Level of Evidence: Level III (Diagnostic).

Motor Strength Measurements Obtained Using an Inexpensive Spring Tensiometer and a Clinical Dynamometer Correlated Well: A Prospective Cohort Study.

OBJECTIVE: Manual muscle strength testing is the primary method for testing muscle strength in clinical settings but is highly subjective. An objective measure of muscle strength can be obtained using a handheld dynamometer, but its cost inhibits its widespread usage. We hypothesized that a spring tensiometer (ST) could be an objective tool that can be used as a viable alternative to a dynamometer. METHODS: Twenty-six outpatients were included, and the strengths of several muscle groups were measured using tensiometers and dynamometers. A paired t-test and Pearson's correlation coefficient and Bland-Altman plot analyses were used to estimate the reliability and measurement accuracy of both tools. Multiple regression analysis was performed to identify the factors contributing to the measurement gap between the two instruments. RESULTS: A total of 260 muscle force values were evaluated. Pearson's correlation coefficient and Bland-Altman analyses indicated that the measurements of the two instruments were strongly correlated and highly accurate. In the multiple regression analysis, the gap between the two instruments was significantly related to the original muscle strength and muscle part but was not significantly related to sex, age, body mass index, or laterality. For biceps and triceps muscle groups, the correlations were particularly strong and accurate, indicating that a tensiometer could be well substituted for a dynamometer. CONCLUSIONS: Our data show that a ST is similar to a dynamometer in terms of precision. A ST is an inexpensive alternative to a dynamometer and more accessible for clinical use than a dynamometer.

Test-retest reliability of isometric shoulder muscle strength during abduction and rotation tasks measured using the Biodex dynamometer.

BACKGROUND: The Constant score (CS) is often used clinically to assess shoulder function and includes a muscle strength assessment only for abduction. The aim of this study was to evaluate the test-retest reliability of isometric shoulder muscle strength during various positions of abduction and rotation with the Biodex dynamometer and to determine their correlation with the strength assessment of the CS. METHODS: Ten young healthy subjects participated in this study. Isometric shoulder muscle strength was measured during 3 repetitions for abduction at 10° and 30° abduction in the scapular plane (with extended elbow and hand in neutral position) and for internal and external rotation (with the arm at 15° abduction in the scapular plane and elbow flexed at 90°). Muscle strength tests with the Biodex dynamometer were measured in 2 different sessions. The CS was acquired only in the first session. Intraclass correlation coefficients (ICCs) with 95% confidence interval, limits of agreement, and paired t tests for repeated tests of each abduction and rotation task were calculated. Pearson's correlation between the strength parameter of the CS and isometric muscle strength was investigated. RESULTS: Muscle strength did not differ between tests (P > .05) with good to very good reliabilities for abduction at 10° and 30°, external rotation and internal rotation (ICC >0.7 for all). A moderate correlation of the strength parameter of the CS with all isometric shoulder strength parameters was observed (r > 0.5 for all). CONCLUSION: Shoulder muscle strength for abduction and rotation measured with the Biodex dynamometer are reproducible and correlate with the strength assessment of the CS. Therefore, these isometric muscle strength tests can be further employed to investigate the effect of different shoulder joint pathology on muscle strength. These measurements consider a more comprehensive functionality of the rotator cuff than the single strength evaluation in abduction within the CS as both abduction and rotation are assessed. Potentially, this would allow for a more precise differentiation between the various outcomes of rotator cuff tears.

Correlação entre resistência de preensão manual e resistência muscular escapular em indivíduos assintomáticos / Correlation between hand grip endurance and scapular muscle endurance in asymptomatic individuals

INTRODUÇÃO: A atividade de preensão é uma ação diária essencial em casa e no local de trabalho, onde muitas vezes é necessário levantar e segurar cargas com uma preensão relativamente estática usando contração isométrica. A força e resistência muscular no aspecto proximal das extremidades superiores influenciam na função da mão, e indivíduos com força e resistência reduzidas são mais propensos a desenvolver distúrbios musculoesqueléticos relacionados ao trabalho. Uma boa resistência de preensão pode ser influenciada pela estabilização fornecida pelos músculos do ombro. Este estudo tem como objetivo determinar a extensão da correlação entre resistência de preensão manual e resistência muscular da escápula em jovens assintomáticos. MÉTODO: O tamanho da amostra para este estudo foi n = 62, com base em estudos anteriores. Indivíduos saudáveis, com idade entre 18 e 25 anos, de ambos os sexos, foram incluídos. Uma avaliação objetiva da resistência da preensão foi realizada usando um dinamômetro manual hidráulico, e a resistência escapular foi avaliada usando o teste muscular escapular. RESULTADOS: A análise de dados foi realizada usando o SPSS versão 20. Houve correlações positivas significativas entre as medidas de resistência escapular e a resistência de preensão palmar para ambos os lados (teste de correlação de Pearson, r = 0,612 (p < 0,001) e r = 0,524 (p < 0,001), respectivamente, para resistência de preensão da mão não dominante e dominante). CONSIDERAÇÕES FINAIS: Os achados preliminares deste estudo sustentam que a resistência do músculo escapular exibe uma relação com a resistência da preensão palmar, sugerindo que o treinamento de resistência escapular pode ser um complemento eficaz no processo de reabilitação das funções da extremidade superior.

INTRODUCTION: Gripping activity is an essential daily activity at home and at the workplace, where lifting and holding loads with a relatively static grip using isometric contraction is often required. Muscle strength and endurance in the proximal aspect of the upper extremities influence hand function, and individuals with reduced strength and endurance are more prone to developing work-related musculoskeletal disorders. Good grip endurance might be influenced by the stabilization provided by shoulder muscles. This study aims to determine the correlation between hand grip endurance and scapula muscle endurance among young asymptomatic individuals. METHOD: The sample size for this study is n = 62, based on previous studies. Healthy individuals of both genders, aged between 18 and 25 years, were included. An objective assessment of grip endurance was performed using a hydraulic hand dynamometer, while scapular endurance was evaluated using the scapular muscle test. RESULTS: Data analysis was performed using SPSS version 20. There were significant positive correlations between scapular endurance measures and the hand grip endurance on both sides (Pearson correlation test, r = 0.612 (p < 0.001) and r = 0.524 (p < 0.001), respectively, for non-dominant and dominant hand grip endurance). FINAL CONSIDERATIONS: The preliminary findings of this study support the notion that scapular muscle endurance is related to hand grip endurance, suggesting that scapular endurance training may be an effective adjunct in the rehabilitation process for upper extremity functions.

Atletas de Taekwondo apresentam desequilíbrio muscular entre os músculos flexores e extensores do joelho: achados preliminares / Taekwondo athletes have muscle imbalance between knee flexors and extensions: preliminary findings / Los atletas de Taekwondo presentan un desequilibrio muscular entre los flexores y los extensores de la rodilla: hallazgos preliminares

Durante a prática de taekwondo com movimentos repetitivos, sistematizados e com certa sobrecarga de treino, o indivíduo pode gerar possíveis adaptações orgânicas que resultam em problemas posturais com grandes chances de desencadear desequilíbrio muscular. Objetivo: Verificar a presença de desequilíbrio entre os grupos musculares agonistas e antagonistas da articulação do joelho e entre membros dominantes e não dominantes de praticantes de taekwondo por meio da dinamometria isocinética. Método: Estudo transversal, observacional e descritivo realizado com nove praticantes de taekwondo do sexo masculino. Utilizou-se um dinamômetro isocinético para investigar o pico de torque, pico de torque por peso corporal, trabalho total, potência média, relação agonista/antagonista e índice de fadiga. Os dados dos membros dominante e não dominante foram comparados por meio do teste t-student para amostras pareadas. Foram calculados o intervalo de confiança de 95% da diferença média, o tamanho de efeito e o poder das análises. Resultados: Os músculos extensores dos membros dominante e não dominante apresentaram diferença média significante de 15,49 Nm (IC95% 7,27; 23,70; p=0,002) para pico de torque e de 22,64% (IC95% 11,83; 33,46; p=0,001) para pico de torque por peso corporal a 60°/s, representando tamanho de efeito médio. Conclusão: Os atletas de taekwondo apresentaram maior pico de torque e maior pico de torque por peso corporal dos músculos extensores do joelho a 60º/s no lado dominante. A relação agonista/ antagonista foi inferior a 60% e mais da metade dos atletas apresentaram uma diferença maior que 10% no pico de torque flexor no lado não dominante.

During taekwondo practice with the repetitive motions, systematized and with certain training overload, the person can generate possible organic adaptations that result in postural problems with a great chances of triggering muscle imbalance. Objective: To verify the presence of imbalance between agonist and antagonist muscle groups of knee joint and between dominant and non-dominant limbs through isokinetic dynamometry. Methods: Cross-sectional, observational and descriptive study realized with nine male taekwondo practitioners. An isokinetic dynamometer was used to investigate the peak torque, peak torque by body weight, total work, average power, agonist/antagonist ratio and fatigue index. Data from the dominant and non-dominant limbs were compared by t-student test for pared samples. The 95% confidence interval of the mean difference, the effect size and the power of analyses power were calculated. Results: The extensor muscles of the dominant and non-dominant limbs showed mean difference of 15,49 Nm (IC95% 7,27; 23,70; p=0,002) for peak torque and of 22,64% (IC95% 11,83; 33,46; p=0,001) for peak torque by body weight at 60°/s, representing average effect size. Conclusion: The taekwondo athletes had higher peak torque and higher peak torque by body weight of the knee extensors muscles in the dominant side. The agonist/ antagonist ratio was less than 60% and more than half of the athletes showed a difference greater than 10% in the peak flexor torque on the non-dominant side.

Durante la práctica de taekwondo con los movimientos repetitivos, sistematizados y con cierta sobrecarga de entrenamiento, la persona puede generar posibles adaptaciones orgánicas que deriven en problemas posturales con grandes posibilidades de desencadenar desequilibrios musculares. Objetivo: Verificar la presencia de desequilibrio entre grupos musculares agonistas y antagonistas de la articulación de la rodilla y entre miembros dominantes y no dominantes mediante dinamometría isocinética. Métodos: Estudio transversal, observacional y descriptivo realizado con nueve practicantes masculinos de taekwondo. Se utilizó un dinamómetro isocinético para investigar el par máximo, el par máximo por peso corporal, el trabajo total, la potencia media, la relación agonista/antagonista y el índice de fatiga. Los datos de las extremidades dominantes y no dominantes se compararon mediante la prueba t- student para muestras de pared. Se calcularon el intervalo de confianza del 95% de la diferencia media, el tamaño del efecto y la potencia de los análisis. Resultados: Los músculos extensores de los miembros dominantes y no dominantes mostraron una diferencia media de 15,49 Nm (IC95% 7,27; 23,70; p=0,002) para el par máximo y de 22,64% (IC95% 11,83; 33,46; p=0,001) para el par máximo por peso corporal a 60°/s, lo que representa el tamaño medio del efecto. Conclusiones: Los atletas de taekwondo presentaron un mayor par máximo y un mayor par máximo por peso corporal de los músculos extensores de la rodilla en el lado dominante. La relación agonista/antagonista fue inferior al 60% y más de la mitad de los atletas mostraron una diferencia superior al 10% en el pico de par flexor en el lado no dominante.

Validity and reliability of a portable handheld dynamometer compared to a fixed isokinetic dynamometer to assess forearm torque strength.

To evaluate the effect of treatment on forearm rotation, torque muscle strength can be assessed using an isokinetic device (IKD) or a wrist dynamometer (WD). The aims of this study were 1) to determine concurrent validity and intra- and inter-rater reliability using the WD, and to examine correlations between WD and IKD in different positions; and 2) subsequently, to establish the intermethod reproducibility between WD as a handheld (HHD) or fixed device. We conducted a cross-sectional study in which torque strength was measured in healthy participants by two observers using an IKD and a WD. Study endpoints were concurrent validity (Pearson's r), intra- and inter-rater reliability, intermethod reproducibility (intraclass correlation coefficient: ICC) and measurement error (limits of agreement: LoA). Concurrent validity ranged, in the 2 studies assessing it, from r 0.37 to 0.52 for pronation and from r 0.50 to 0.82 for supination, with wide 95% confidence intervals. ICC for intra-rater reliability for pronation ranged from 0.85 to 0.91 and for supination from 0.91 to 0.95. ICC for inter-rater reliability for pronation ranged from 0.84 to 0.96 and for supination from 0.92 to 0.96. Despite the excellent intra- and inter-rater reliability and intermethod reproducibility for the WD-HHD and fixed WD, validity was low when compared to IKD and wide LoA indicated a high measurement error of approximately 20%. These results suggest that the WD cannot replace the IKD isometric mode for pronation and supination. LEVEL OF EVIDENCE: 2.

Validity, reliability and test-retest study of Grip strength measurement in two positions with two dynamometers: Jamar® Plus and K-Force® Grip.

Our objective was to compare grip strength measurement in two body positions (sitting and standing) with the K-Force® Grip dynamometer and the Jamar® Plus Digital hand dynamometer, and to conduct a test-retest study of the K-Force Grip device. The study was conducted on 50 healthy young adults aged 18-25 years. Maximal grip strength was tested in sitting and standing positions with both devices. After 2 days, a re-test was conducted with the K-Force Grip. The correlation coefficient was high for grip strength measurements in sitting and standing positions with the K-Force Grip and Jamar Plus dynamometers (r > 0.9 for all). K-Force Grip values were similar in sitting and standing positions (p > 0.05). Despite this similarity, K-Force Grip measured significantly lower values than Jamar Plus (p < 0.05). Thus, the K-Force Grip device can be used as an alternative to the Jamar Plus dynamometer, regarded as the gold standard in evaluating grip strength. We believe that the same devices should be used in clinical studies, research, and patient follow-up.

Muscle architecture of the vastus lateralis and rectus femoris in the production of knee extensor torque in physically inactive women

Abstract Aim: This study aimed to verify the data reliability of muscle architecture (MA) variables, and the relationship between MA and the isometric peak torque (PT) of the monoarticular and biarticular knee extensor (KE) muscle in physically inactive women. Methods: Ten physically inactive women (24.0 ± 1.64 years; 162.9 ± 5.34 cm; 63.5 ± 11.90 kg) participated in the study. An ultrasound device assessed the MA variables (muscle thickness, fascicle length, and pennation angle) of the Vastus Lateralis (VL) and Rectus Femoris (RF), and an isokinetic dynamometer assessed the PT. Pearson correlation evaluated the relationship between PT and MA variables, with a significance level of 5%. Additionally, the intraclass correlation coefficient, coefficient of variation, and standard error of measurement. Results: Excellent reliability between images was observed, and no significant relationships were observed between the PT and MA variables of the VL and RF. Conclusion: Isolated variables of the MA of a monoarticular or a biarticular muscle do not influence the production of the isometric PT of the KE.

Efecto de la práctica mental kinestésica en la fuerza y actividad mioeléctrica del bíceps braquial, luego de un periodo de inmovilización de codo en adultos-jóvenes sanos / Effects of kinesthetic mental practice in strength and myoelectric activity of the brachialis biceps due to an elbow immobilization period in healthy young adults

RESUMEN: El objetivo de este estudio fue determinar el efecto de la práctica mental kinestésica (PMK) en la fuerza y actividad eléctrica muscular (AEM) del bíceps braquial, luego de un periodo de inmovilización del codo en un grupo de personas adultos jóvenes sanos. Un total de 14 personas (18,64 ± 0,92 años de edad) participaron voluntariamente del estudio, a las cuales se les evaluó la fuerza muscular de prensión y la AEM del bíceps braquial utilizando un dinamómetro de mano y un equipo de electromiografía, respectivamente, antes y después de un periodo de inmovilización del brazo no dominante, y se asignaron aleatoriamente a uno de dos grupos: grupo control (GC) o experimental (GE). El GE realizó PMK: tres series de 15 repeticiones con un minuto de descanso entre series, tres veces al día durante los seis días de inmovilización, mientras que el GC no realizó PKM durante su inmovilización. Al aplicar una prueba de ANOVA de dos vías, no se encontraron diferencias significativas en la fuerza ni en la AEM. Sin embargo, la fuerza del GC disminuyó en 23,75%, mientras que la del GE aumentó en 33,19%. Los resultados sugieren que un periodo de inmovilización del codo de seis días no fue suficiente para que la fuerza ni la AEM disminuyan significativamente, lo que supone que la PMK realizada no es necesaria en periodos menores a seis días.

ABSTRACT: The aim of this study was to determine the effect of kinesthetic mental practice (KMP) on the strength and muscular electrical activity (MEA) of the brachial biceps, after a period of immobilization of the elbow in a group of healthy young adults. A total of 14 volunteer participants (18.64 ± 0.92 years of age) were part in the study. The muscle strength and the AEM of the brachial biceps were assessed using a hand dynamometer and an electromyography equipment, respectively, before and after a period of immobilization of the non-dominant arm. After the pretest, they were randomly assigned to one of two groups: control group (GC) or experimental group (GE). The GE performed 3 sets of 15 repetitions with one-minute rest between sets, three times a day of PMK during the 6 days of immobilization, while the GC did not perform PKM during its immobilization. A 2-way ANOVA test (group x measurement) indicated non-significant differences in strength or AEM. However, the strength of the GC decreased by 23.75%, while increased by 33.19% in the GE. The results suggest that a period of immobilization of the elbow of 6 days was not enough for the strength or the AEM to decrease significantly, which means that the PMK is not necessary in periods of immobilization of less than 6 days.

Comparative analysis of the influence of handgrip strength mobility on the quality of life of institutionalized elderly / Análise comparativa da influência da força e mobilidade da preensão manual na qualidade de vida de idosos institucionalizados

The objective of this study was to carry out a comparative analysis between handgrip strength and mobility in the quality of life (QOL) of older adults living in long-term care facilities. Methods: This was a cross sectional study conducted in Belo Horizonte, Brazil, comprised of a sample population of 127 older adults. Measurements included the World Health Organization Quality of Life-OLD (WHOQOL-BREF) questionnaire, assessment of the handgrip strength by hand dyna- mometer and mobility by Timed Up and Go (TUG). An analysis of variance (ANOVA) was performed to compare the mean values of the WHOQOL-BREF, global and domains, in each stratum of the hand grip strength and mobility values. Our results showed that handgrip dynamometer strength was associated with higher perception of the global WHOQOL-BREF score and two WHOQOL-BREF domains environment (p<0.028) and physical health (p<0.002), that is, the highest QOL values were seen in those older adults with greater handgrip strength. However, no significant association between TUG score and any quality of life domains was found. It can be inferred that handgrip strength seems to influence the quality of life of institutionalized older adults and healthcare providers in LTCs should account for when designing interventions.(AU)

O objetivo desse estudo foi realizar uma análise comparativa entre a força de preensão manual e a mobilidade na qualidade de vida de idosos residentes em Instituições de longa permanência. Este foi um estudo transversal conduzido no município de Belo Hori- zonte, Brasil, envolvendo uma amostra de 127 idosos institucionalizados. As medidas incluíram os questionários de Qualidade de Vida propostos pela Organização Mundial de Saúde (WHOQOL- BREF), avaliação da força de preensão manual pelo dinamômetro manual e a mobilidade pelo Timed Up and Go (TUG). Foi realizada uma análise de variância (ANOVA) para comparar os valores médios do WHOQOL BREF, total e por domínio, em cada estrato dos valores da força de preensão manual e de mobilidade. Os resultados mostraram que foram observados diferenças significativas nos escore global do WHOQOL BREF e nos domínios meio ambiente (p<0.028) e físico (p<0.002) entre os estratos da força de preensão manual, ou seja, os maiores valores da QV foram vistos naqueles idosos com maior força de preensão. Por outro lado, não houve diferença nas médias do WHOQOL, total e por domínio, em nenhum dos estratos do TUG. Pode-se inferir que a força de preensão parece influenciar na qualidade de vida em idosos institucionalizados, devendo, pois, aos gestores das instituições de longa permanência levar em consideração essa informação ao propor intervenções para essa população.(AU)

A prospectively collected observational study of pelvic floor muscle strength and erectile function using a novel personalized extracorporeal perineometer.

To investigate the association between pelvic floor muscle strength and erectile function in a prospectively collected observational cohort. 270 male volunteers were prospectively collected and grouped by International Index of Erectile Function-5 (IIEF-5) scores. Pelvic floor muscle strength was compared. Patients with obvious neurologic deficits, abnormal pelvic bones, history of pelvic radiation therapy, prostatectomy, or urinary incontinence were excluded. We analyzed 247 patients with mean (± standard deviation, SD) age of 62.8 (± 10.1) years. Mean (± SD) maximal and average strength were 2.0 (± 1.5) and 1.1 (± 0.8) kgf, respectively. Mean (± SD) endurance and IIEF-5 scores were 7.2 (± 2.6) seconds and 13.3 (± 7.9), respectively. Patients with IIEF-5 scores ≤ 12 tended to be older, with a higher occurrence of hypertension and lower body mass index. Age [odds ratio (OR) 1.08, 95% confidence interval (CI) 1.04-1.12, p < 0.001], and maximal strength < 1.9 kgf (OR 2.62, 95% CI 1.38-4.97, p = 0.003) were independent predictors for IIEF-5 scores ≤ 12 in multivariate regression analysis. Patients with erectile dysfunction were older and showed lower pelvic floor muscle maximal strength. Future prospective trials needed for using physiotherapy are required to verify our results.

Relationship of the hip and trunk muscles with the dynamic knee valgus in asymptomatic young women / Relação dos músculos do quadril e tronco com o valgo dinâmico de joelho em mulheres jovens assintomáticas

The presence of severe dynamic knee valgus in asymptomatic women may be a factor related to future complaints of pain in this joint. The aim of this study is to correlate the strength levels of hip and trunk stabilizer muscles with knee valgus angles, pelvic and trunk tilt in asymptomatic young women. 22 young women with no history of lower limb pain or injury participated in this study. In the first visit to the laboratory, the volunteers performed anamnesis, kinematic evaluation of the dynamic knee valgus angle, pelvic and trunk tilt. Afterwards, familiarization with muscle strength tests was made. On the second day, the evaluation of the maximal isometric muscle strength of the hip stabilizer muscles (lateral rotators, hip abductors and extensors) and trunk extensors was performed, using a hand dynamometer. For analysis of muscle strength data, the joint torque peak was used and, in relation to the kinematic data, the knee projection angles in the frontal plane, pelvis and trunk tilt, through the Kinovea software. Pearson's Correlation test showed no relationship between the hip and trunk muscle torque and the kinematic angles during the frontal and lateral step down. The muscle torque of the hip stabilizers and trunk extensors are not related to the movement pattern of the volunteers during the step down.(AU)

O valgo dinâmico de joelho em mulheres assintomáticas pode ser um fator de risco relacionado com queixas futuras de dor nessa articulação. O objetivo deste estudo é investigar a relação entre torque articular da musculatura estabilizadora do quadril e tronco com a cinemática do teste step down em mulheres jovens assintomáticas. Participaram deste estudo 22 mulheres, com idade média de 22,5 anos (±2,06), sem histórico de dor ou lesão em membros inferiores. Na primeira visita ao laboratório, as voluntárias realizaram anamnese, avaliação cinemática durante o teste step down frontal e lateral. No segundo dia, foi realizada a avalia ção do torque articular isométrico máximo de rotação lateral, abdução e extensão do quadril e extensão de tronco, utilizando um dinamometro manual. Para análise dos dados, foi utilizado o pico de torque articular dos movimentos avaliados e em relação aos dados cinemáticos, foi calculado os ângulos de projeção de joelho no plano frontal, inclinação da pelve e tronco, por meio do software Kinovea. O teste de Correlação de Pearson não mostrou relação entre o torque muscular de quadril e tronco com os ângulos cinemáticos durante o step down frontal e lateral. Portanto, concluímos que o torque muscular máximo dos estabilizadores lombo pélvicos não estão correlacionados com o padrão de movimento cinemático durante o teste step down.(AU)

Reliability of Handheld Dynamometry to Measure Focal Muscle Weakness in Neurofibromatosis Types 1 and 2.

OBJECTIVE: To determine a suitable outcome measure for assessing muscle strength in neurofibromatosis (NF) type 1 and NF2 clinical trials, we evaluated the intraobserver reliability of handheld dynamometry (HHD) and developed consensus recommendations for its use in NF clinical trials. METHODS: Patients ≥5 years of age with weakness in at least 1 muscle group by manual muscle testing (MMT) were eligible. Maximal isometric muscle strength of a weak muscle group and the biceps of the dominant arm was measured by HHD. An average of 3 repetitions per session was used as an observation, and 3 sessions with rest period between each were performed on the same day by a single observer. Intrasession and intersession intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) were calculated to assess reliability and measurement error. RESULTS: Twenty patients with NF1 and 13 with NF2 were enrolled; median age was 12 years (interquartile range [IQR] 9-17 years) and 29 years (IQR 22-38 years), respectively. By MMT, weak muscle strength ranged from 2-/5 to 4+/5. Biceps strength was 5/5 in all patients. Intersession ICCs for the weak muscles were 0.98 and 0.99 in the NF1 and NF2 cohorts, respectively, and for biceps were 0.97 and 0.97, respectively. The median CVs for average session strength were 5.4% (IQR 2.6%-7.3%) and 2.9% (IQR 2.0%-6.2%) for weak muscles and biceps, respectively. CONCLUSION: HHD performed by a trained examiner with a well-defined protocol is a reliable technique to measure muscle strength in NF1 and NF2. Recommendations for strength testing in NF1 and NF2 trials are provided.

Effects of resistance training at different intensities of load on cross-education of muscle strength.

The objectives of this study were to 1) compare the extent of cross-transfer of muscle strength of high- versus low-load unilateral resistance training performed with external pacing of the movement (URTEP) and 2) compare the time course of the 2 approaches. Fifty subjects were randomized to 1 of the following 3 groups: G80 [2 sets at 80% and 2 sets at 40% of 1 repetition maximum (1RM), 1 concentric second and 3 eccentric seconds controlled by a metronome]; G40 (4 sets at 40% of 1RM, 1 s and 3 s controlled by a metronome); or control group. At week 1, the G80 increased the elbow flexion 1RM (P < 0.05) in contralateral arm. At week 4, both G80 and G40 increased the elbow flexion 1RM (P < 0.05) in contralateral arm. However, a greater 1RM gain was observed in the G80 than in the G40 (P < 0.05). Thus, although higher-load URTEP seems to enhance the cross-education effect when compared with lower-load URTEP, the cross-education of dynamic strength can be achieved in the 2 approaches after 4 weeks. Many patients would benefit from cross-education of muscle strength through URPEP, even those who are unable to exercise with high loads and in short periods of immobilization. Novelty: Unilateral resistance training promotes cross-education of dynamic muscle strength. However, higher-load resistance training enhances the effects of cross-education of muscle strength.

Price of a Finger.

Background: Traumatic loss of an index finger is offered twice the amount of compensation as compared to a loss of little finger. However, the little finger plays a pivotal role in power grip thus is underestimated in its importance. Our aim was to test our hypothesis that loss of the little finger will result in greater or equal loss of grip strength compared to loss of the index finger. Methods: Grip strength in the power grip position was measured in 12 healthy volunteers using a JAMAR hand dynamometer. Grip strength of their dominant hand was recorded as a mean kg force of three attempts in three grip configurations 1) using all fingers 2) excluding the index finger and 3) excluding the little finger. Grip strength percentage compared to the full hand was calculated and statistical significance was investigated with a two-tailed T-test. Results: Participants' age varied from 19-64 years, with 4 males and 8 females. Mean full hand grip strength was 28.3 kg force; grip strength with index finger excluded was 65.8% and with little finger excluded was 66.2%. There was no significant difference in grip strength percentage when comparing index or little finger exclusion (p = 0.92). Conclusions: We did not find a difference in power grip using a simulated model of index or little finger loss in a healthy volunteer cohort. This should be taken into account in traumatic loss and work compensation.

Delayed onset muscle soreness intensity affects muscular performance / El Dolor muscular de aparición tardía afecta el desempeño muscular

Abstract Background: The study of functional impact of delayed onset muscle soreness has been limited to describe the decline on maximal isometric contraction, but muscular work and time to peak torque has not been examined yet. Purpose: To describe the changes induced by a session of lengthening contractions on muscle performance and delayed onset muscle soreness (DOMS). Methods: A quasi-experimental study was conducted in the Institutional laboratory; Twenty healthy men; mean age 21 SD 0.34 were recruited, all subjects performed 200 lengthening contractions of the quadriceps at 120°/s. Isometric and isokinetic peak torque, muscular work, time to peak torque, DOMS and creatine kinase activity were assessed at baseline, 48 h and 96 h post-exercise. The muscle performance was assessed with an isokinetic dynamometer and DOMS with a visual analog scale (VAS). Results: Relative to baseline, isometric and isokinetic peak torque and muscular work decreased in ~30% at 48 h post-exercise; delayed onset muscle soreness increased ~300%, which remained at 96 h post-exercise. Conclusions: These reflect that the decline in muscular performance is due to the changes in peak torque and muscular work, which has greater implications on muscle function. No changes were detected in time to peak torque. The alterations in muscular performance variables are accompanied by delayed onset muscle soreness which has also a negative impact on force production (29% of the drop on peak torque is explain by soreness intensity).

Resumen Introducción: Los estudios de impacto funcional del dolor muscular de aparición tardía (DMAT) se han limitado a describir la disminución de la contracción isométrica máxima, pero aún no se ha examinado el trabajo muscular y el tiempo del torque máximo. Objetivo: Describir los cambios inducidos por una sesión de ejercicio excéntrico sobre el rendimiento muscular y DMAT. Método: se realizó un estudio cuasi-experimental, los participantes fueron veinte hombres sanos; edad media 21 DE 0,34, todos los sujetos realizaron 200 contracciones excéntricas del cuádriceps a 120°/s. Se evaluó el torque pico isométrico e isocinético, el trabajo muscular, el tiempo hasta el torque máximo, DMAT y la actividad de la creatina quinasa al inicio, 48 h y 96 h después del ejercicio, el rendimiento muscular se evaluó con un dinamómetro isocinético y DOMS con una escala análoga visual (EAV). Resultados: en relación con la línea de base, el torque pico isométrico e isocinético y el trabajo muscular disminuyeron en ~ 30 % a las 48 h post-ejercicio; El dolor muscular de aparición tardía aumentó ~300 %, que permaneció 96 h después del ejercicio. Conclusiones: los resultados reflejan que la disminución del rendimiento muscular se debe a los cambios en el torque pico y trabajo muscular, lo que tiene mayores implicaciones en la función muscular. No se detectaron cambios en el tiempo hasta el torque máximo. Las alteraciones en las variables de rendimiento muscular se acompañan de DMAT que también tiene un impacto negativo en la producción de fuerza (el 29 % de la caída en el torque máximo se explica por la intensidad del dolor).